A structure is known that transmits an impact load that is input from a side of a vehicle during a collision or the like towards the vehicle floor via the seats (see, for example, Patent document 1). Specifically, in the vehicle seat described in Patent document 1, framework portions of the seat (i.e., the plate components and the top cross member) extend towards an outer side in the vehicle transverse direction beyond the seat back frame, and a load transmitting block is mounted such that it covers this extended portion.
In this seat back frame, when an impact load is input from the vehicle side portion, this load is transmitted to a side frame portion on an outer side in the vehicle transverse direction via the load transmitting components. Furthermore, the load is also transmitted from this side frame portion to a side frame portion on an inner side in the vehicle transverse direction via the plate components on the rear side and via the top cross member.
In addition to this, a structure is also known that transmits an impact load that is input from a side of the vehicle during a collision or the like towards the vehicle floor via the seats (see, for example, Patent document 3).
Specifically, the seat back frame described in Patent document 3 is provided with a pair of side frame portions that are placed on both sides in the vehicle transverse direction, a load transmitting piece that protrudes from a side frame portion on the outer side in the vehicle transverse direction towards the outer side in the vehicle transverse direction, and a load transmitting component that extends from substantially the same height as the load transmitting pieces on the side frame portion on the outer side in the vehicle transverse direction at an inclined attitude towards a bottom portion of a side frame portion on the inner side in the vehicle transverse direction. Moreover, a reclining shaft that is placed so as to bridge the gap between the side frame portions, and so as to support the side frame portions such that they are able to pivot is provided at a bottom end portion of the side frame portions.
According to this structure, while an impact load that is input into a bottom portion of a vehicle side wall is transmitted from the side frame portion on the outer side in the vehicle transverse direction to the side frame portion on the inner side in the vehicle transverse direction via the reclining shaft, in contrast, an impact load that is input into a top portion of a vehicle side wall is transmitted from the load transmitting piece to the side frame portion on the inner side in the vehicle transverse direction via the load transmitting component.